Soil series profile

Kokomo soil series

Kokomo is a very poorly drained soil with a silty clay loam surface, mapped on 371,896 acres in 35 counties across 3 states. Hydrologic group C/D.

#858 by mapped area fine Typic Argiaquolls (Mollisols)

Drainage class
Very poorly drained
92% of mapped acres
Hydrologic group
C/D
98% of mapped acres
Typical topsoil pH
6.2
slightly acidic · range 6.2–6.5
Mapped area
372k
acres in 35 counties, 3 states

Typical Kokomo profile

Texture and pH by depth

Typical Kokomo soil profile by depth 0 in 20 in 40 in 60 in 0–11 in · Ap · pH 6.2 · 31% clay Silty clay loam 11–41 in · Btg · pH 6.5 · 36% clay Clay loam 41–64 in · Bt · pH 6.7 · 36% clay Clay loam 64–79 in · 2C · pH 7.9 · 22% clay Loam
Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).
Show as a table
Typical Kokomo horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–11 in (Ap) Silty clay loam 6.2 31% 20% 4.5%
11–41 in (Btg) Clay loam 6.5 36% 22% 1.5%
41–64 in (Bt) Clay loam 6.7 36% 22% 1.5%
64–79 in (2C) Loam 7.9 22% 40% 0.1%

Representative values from the most extensive Kokomo map unit (Kokomo silty clay loam, 0 to 2 percent slopes, survey area OH097). Other map units of this series vary within the series range.

Hands holding dark garden soil
Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Kokomo soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Kokomo soils is slightly acidic: pH 6.2 (most land between 6.2 and 6.5), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 98% of mapped Kokomo acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silty clay loam (91% of mapped Kokomo acres).

98% of mapped Kokomo acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.

For lawns and yards

On 98% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

A seasonal high water table comes within 18 inches of the surface on 98% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.

For a septic system

For conventional septic absorption fields, NRCS rates 98% of the acres in mapped Kokomo soils very limited, 0% somewhat limited and 0% not limited (2% not rated, such as urban land, pits or water).

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Kokomo soil is found

Mapped acres

Kokomo is mapped in Ohio, Indiana and Michigan.

Counties with the most mapped Kokomo soil
County Acres Share of county land
Madison County, OH 101,104 33.9%
Pickaway County, OH 58,427 18.2%
Franklin County, OH 42,646 12.4%
Preble County, OH 41,836 15.4%
Clark County, OH 36,790 14.5%
Ross County, OH 19,015 4.3%
Clinton County, OH 14,468 5.5%
Fayette County, OH 9,361 3.6%
Darke County, OH 6,490 1.7%
Miami County, OH 5,762 2.2%
Champaign County, OH 5,368 2.0%
Montgomery County, OH 4,631 1.6%
Fairfield County, OH 4,372 1.4%
Lenawee County, MI 4,209 0.9%
Greene County, OH 3,538 1.3%
Madison County, IN 2,737 1.0%
Wayne County, IN 2,726 1.1%
Hancock County, IN 1,370 0.7%
Shelby County, OH 1,268 0.5%
Logan County, OH 1,010 0.3%
Howard County, IN 956 0.5%
Henry County, IN 793 0.3%
Ionia County, MI 753 0.2%
Highland County, OH 728 0.2%
Union County, OH 607 0.2%
Butler County, OH 394 0.1%
Shelby County, IN 299 0.1%
Rush County, IN 161 0.1%
Fayette County, IN 46 0.0%
Decatur County, IN 11 0.0%
Clinton County, IN 9 0.0%
Union County, IN 8 0.0%
Vigo County, IN 3 0.0%
Tipton County, IN 1 0.0%
Hocking County, OH 0 0.0%

Septic absorption fields

NRCS rating, share of Kokomo acres

Not limited 0%
Somewhat limited 0%
Very limited 98%
Not rated 2%
Septic tank absorption field rating across mapped Kokomo acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Kokomo acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited98.0%
Not rated2.0%

Drainage, water table and flooding

Share of Kokomo acres

Depth to seasonal high water table
About 2 inches (median where reported); within 18 inches on 98% of acres.
Flooding
Not mapped as flooding on most acres.
Slope
Typically 0–1% (median 1%).
Topsoil organic matter
Median 4.5%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 0%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 6%
Very poorly drained 92%
Not rated 2%
Drainage class across mapped Kokomo acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Kokomo acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained0.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained5.9%
Very poorly drained92.4%
Not rated1.8%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 0%
D: very slow infiltration (clayey, shallow or wet) 0%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained <1%
C/D: D as is, C if drained 98%
Not rated 2%
Hydrologic soil group across mapped Kokomo acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Kokomo acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration0.0%
D: very slow infiltration (clayey, shallow or wet)0.0%
A/D: D as is, A if drained0.0%
B/D: D as is, B if drained0.3%
C/D: D as is, C if drained97.7%
Not rated2.0%

Sources & data dates

Source
USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date
SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope
All map unit components named Kokomo (component kind "Series") in SSURGO: 371,896 acres.
Method
Shares are by mapped acres of Kokomo components. The profile comes from the single largest Kokomo component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Kokomo.